Theorem prel12g 4387

Description: Closed form of prel12 4383. (Contributed by AV, 9-Dec-2018.)

Assertion

Ref	Expression
prel12g	|- ( ( ( A e. V /\ B e. W ) /\ ( C e. X /\ D e. Y ) ) -> ( -. A = B -> ( { A , B } = { C , D } <-> ( A e. { C , D } /\ B e. { C , D } ) ) ) )

Proof of Theorem prel12g

Dummy variables x y z w are mutually distinct and distinct from all other variables.

Step	Hyp	Ref	Expression
1		eqeq1 2626	. . . . . . 7 |- ( x = A -> ( x = y <-> A = y ) )
2	1	notbid 308	. . . . . 6 |- ( x = A -> ( -. x = y <-> -. A = y ) )
3		preq1 4268	. . . . . . . 8 |- ( x = A -> { x , y } = { A , y } )
4	3	eqeq1d 2624	. . . . . . 7 |- ( x = A -> ( { x , y } = { z , D } <-> { A , y } = { z , D } ) )
5		eleq1 2689	. . . . . . . 8 |- ( x = A -> ( x e. { z , D } <-> A e. { z , D } ) )
6	5	anbi1d 741	. . . . . . 7 |- ( x = A -> ( ( x e. { z , D } /\ y e. { z , D } ) <-> ( A e. { z , D } /\ y e. { z , D } ) ) )
7	4, 6	bibi12d 335	. . . . . 6 |- ( x = A -> ( ( { x , y } = { z , D } <-> ( x e. { z , D } /\ y e. { z , D } ) ) <-> ( { A , y } = { z , D } <-> ( A e. { z , D } /\ y e. { z , D } ) ) ) )
8	2, 7	imbi12d 334	. . . . 5 |- ( x = A -> ( ( -. x = y -> ( { x , y } = { z , D } <-> ( x e. { z , D } /\ y e. { z , D } ) ) ) <-> ( -. A = y -> ( { A , y } = { z , D } <-> ( A e. { z , D } /\ y e. { z , D } ) ) ) ) )
9	8	imbi2d 330	. . . 4 |- ( x = A -> ( ( D e. Y -> ( -. x = y -> ( { x , y } = { z , D } <-> ( x e. { z , D } /\ y e. { z , D } ) ) ) ) <-> ( D e. Y -> ( -. A = y -> ( { A , y } = { z , D } <-> ( A e. { z , D } /\ y e. { z , D } ) ) ) ) ) )
10		eqeq2 2633	. . . . . . 7 |- ( y = B -> ( A = y <-> A = B ) )
11	10	notbid 308	. . . . . 6 |- ( y = B -> ( -. A = y <-> -. A = B ) )
12		preq2 4269	. . . . . . . 8 |- ( y = B -> { A , y } = { A , B } )
13	12	eqeq1d 2624	. . . . . . 7 |- ( y = B -> ( { A , y } = { z , D } <-> { A , B } = { z , D } ) )
14		eleq1 2689	. . . . . . . 8 |- ( y = B -> ( y e. { z , D } <-> B e. { z , D } ) )
15	14	anbi2d 740	. . . . . . 7 |- ( y = B -> ( ( A e. { z , D } /\ y e. { z , D } ) <-> ( A e. { z , D } /\ B e. { z , D } ) ) )
16	13, 15	bibi12d 335	. . . . . 6 |- ( y = B -> ( ( { A , y } = { z , D } <-> ( A e. { z , D } /\ y e. { z , D } ) ) <-> ( { A , B } = { z , D } <-> ( A e. { z , D } /\ B e. { z , D } ) ) ) )
17	11, 16	imbi12d 334	. . . . 5 |- ( y = B -> ( ( -. A = y -> ( { A , y } = { z , D } <-> ( A e. { z , D } /\ y e. { z , D } ) ) ) <-> ( -. A = B -> ( { A , B } = { z , D } <-> ( A e. { z , D } /\ B e. { z , D } ) ) ) ) )
18	17	imbi2d 330	. . . 4 |- ( y = B -> ( ( D e. Y -> ( -. A = y -> ( { A , y } = { z , D } <-> ( A e. { z , D } /\ y e. { z , D } ) ) ) ) <-> ( D e. Y -> ( -. A = B -> ( { A , B } = { z , D } <-> ( A e. { z , D } /\ B e. { z , D } ) ) ) ) ) )
19		preq1 4268	. . . . . . . 8 |- ( z = C -> { z , D } = { C , D } )
20	19	eqeq2d 2632	. . . . . . 7 |- ( z = C -> ( { A , B } = { z , D } <-> { A , B } = { C , D } ) )
21	19	eleq2d 2687	. . . . . . . 8 |- ( z = C -> ( A e. { z , D } <-> A e. { C , D } ) )
22	19	eleq2d 2687	. . . . . . . 8 |- ( z = C -> ( B e. { z , D } <-> B e. { C , D } ) )
23	21, 22	anbi12d 747	. . . . . . 7 |- ( z = C -> ( ( A e. { z , D } /\ B e. { z , D } ) <-> ( A e. { C , D } /\ B e. { C , D } ) ) )
24	20, 23	bibi12d 335	. . . . . 6 |- ( z = C -> ( ( { A , B } = { z , D } <-> ( A e. { z , D } /\ B e. { z , D } ) ) <-> ( { A , B } = { C , D } <-> ( A e. { C , D } /\ B e. { C , D } ) ) ) )
25	24	imbi2d 330	. . . . 5 |- ( z = C -> ( ( -. A = B -> ( { A , B } = { z , D } <-> ( A e. { z , D } /\ B e. { z , D } ) ) ) <-> ( -. A = B -> ( { A , B } = { C , D } <-> ( A e. { C , D } /\ B e. { C , D } ) ) ) ) )
26	25	imbi2d 330	. . . 4 |- ( z = C -> ( ( D e. Y -> ( -. A = B -> ( { A , B } = { z , D } <-> ( A e. { z , D } /\ B e. { z , D } ) ) ) ) <-> ( D e. Y -> ( -. A = B -> ( { A , B } = { C , D } <-> ( A e. { C , D } /\ B e. { C , D } ) ) ) ) ) )
27		preq2 4269	. . . . . . . . 9 |- ( w = D -> { z , w } = { z , D } )
28	27	eqeq2d 2632	. . . . . . . 8 |- ( w = D -> ( { x , y } = { z , w } <-> { x , y } = { z , D } ) )
29	27	eleq2d 2687	. . . . . . . . 9 |- ( w = D -> ( x e. { z , w } <-> x e. { z , D } ) )
30	27	eleq2d 2687	. . . . . . . . 9 |- ( w = D -> ( y e. { z , w } <-> y e. { z , D } ) )
31	29, 30	anbi12d 747	. . . . . . . 8 |- ( w = D -> ( ( x e. { z , w } /\ y e. { z , w } ) <-> ( x e. { z , D } /\ y e. { z , D } ) ) )
32	28, 31	bibi12d 335	. . . . . . 7 |- ( w = D -> ( ( { x , y } = { z , w } <-> ( x e. { z , w } /\ y e. { z , w } ) ) <-> ( { x , y } = { z , D } <-> ( x e. { z , D } /\ y e. { z , D } ) ) ) )
33	32	imbi2d 330	. . . . . 6 |- ( w = D -> ( ( -. x = y -> ( { x , y } = { z , w } <-> ( x e. { z , w } /\ y e. { z , w } ) ) ) <-> ( -. x = y -> ( { x , y } = { z , D } <-> ( x e. { z , D } /\ y e. { z , D } ) ) ) ) )
34		vex 3203	. . . . . . 7 |- x e. _V
35		vex 3203	. . . . . . 7 |- y e. _V
36		vex 3203	. . . . . . 7 |- z e. _V
37		vex 3203	. . . . . . 7 |- w e. _V
38	34, 35, 36, 37	prel12 4383	. . . . . 6 |- ( -. x = y -> ( { x , y } = { z , w } <-> ( x e. { z , w } /\ y e. { z , w } ) ) )
39	33, 38	vtoclg 3266	. . . . 5 |- ( D e. Y -> ( -. x = y -> ( { x , y } = { z , D } <-> ( x e. { z , D } /\ y e. { z , D } ) ) ) )
40	39	a1i 11	. . . 4 |- ( ( x e. V /\ y e. W /\ z e. X ) -> ( D e. Y -> ( -. x = y -> ( { x , y } = { z , D } <-> ( x e. { z , D } /\ y e. { z , D } ) ) ) ) )
41	9, 18, 26, 40	vtocl3ga 3276	. . 3 |- ( ( A e. V /\ B e. W /\ C e. X ) -> ( D e. Y -> ( -. A = B -> ( { A , B } = { C , D } <-> ( A e. { C , D } /\ B e. { C , D } ) ) ) ) )
42	41	3expa 1265	. 2 |- ( ( ( A e. V /\ B e. W ) /\ C e. X ) -> ( D e. Y -> ( -. A = B -> ( { A , B } = { C , D } <-> ( A e. { C , D } /\ B e. { C , D } ) ) ) ) )
43	42	impr 649	1 |- ( ( ( A e. V /\ B e. W ) /\ ( C e. X /\ D e. Y ) ) -> ( -. A = B -> ( { A , B } = { C , D } <-> ( A e. { C , D } /\ B e. { C , D } ) ) ) )

Syntax hints:   -. wn 3   -> wi 4   <-> wb 196   /\ wa 384   /\ w3a 1037   = wceq 1483   e. wcel 1990   {cpr 4179

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1722  ax-4 1737  ax-5 1839  ax-6 1888  ax-7 1935  ax-9 1999  ax-10 2019  ax-11 2034  ax-12 2047  ax-13 2246  ax-ext 2602

This theorem depends on definitions:  df-bi 197  df-or 385  df-an 386  df-3an 1039  df-tru 1486  df-ex 1705  df-nf 1710  df-sb 1881  df-clab 2609  df-cleq 2615  df-clel 2618  df-nfc 2753  df-v 3202  df-un 3579  df-sn 4178  df-pr 4180

This theorem is referenced by:  hash2prd  13257